Organic Compounds in Water and Wastewater Cyanotoxins Removal in - - PowerPoint PPT Presentation

CEE 697z

Organic Compounds in Water and Wastewater

Cyanotoxins Removal in Water Treatment

CEE 697z - Lecture #30

Print version

Lecture #30

WRF Reports on Cyanotoxin Control

 Newcombe, 2002 (WRF 446) Removal of Algal Toxins from

Drinking Water Using ozone and GAC

 WRF 2839; Treatability of Algal Toxins using Oxidation,

Adsorption and Membrane Technologies (2010)

 Newcombe, 2009 (WRF 3148) International Guidance Manual

for the Management of Toxic Cyanobacteria, Global Water Research Coalition Project (2010)

 WRF 4016; Evaluation of Integrated Membrane Systems for

T&O and Algal Toxin Control (2012)

 Wert et al., 2014 (WRF 4406) Release of Intracellular

metabolites from Cyanobacteria during Oxidation Processes

 Newcombe, 2015? (WRF 4315) Optimizing Conventional

Treatment for Removal of Cyanobacteria and Toxins (in progress)

• Fig. 6 Overview of drinking

water treatment and the

• verall impact on

cyanobacteria and cyanotoxins.

Merel, S., Walker, D., Chicana, R., Snyder, S., Baures, E. and Thomas, O. (2013) State of knowledge and concerns on cyanobacterial blooms and

• cyanotoxins. Environment

International 59, 303-327.

Water Treatment

Chlorine and Mycrosystins

• Fig. 2 Formation
• f dihydroxy-

microcystin from reaction with chlorine

Merel, S., Walker, D., Chicana, R., Snyder, S., Baures, E. and Thomas, O. (2013) State of knowledge and concerns on cyanobacterial blooms and

• cyanotoxins. Environment

International 59, 303-327.

Chlorination

• Fig. 3 Formation of

5-chloro- cylindrospermopsin and cylindrospermopsic acid from reaction with chlorine

Merel, S., Walker, D., Chicana, R., Snyder, S., Baures, E. and Thomas, O. (2013) State of knowledge and concerns on cyanobacterial blooms and

• cyanotoxins. Environment

International 59, 303-327.

Chlorination

Ozone and Cyanotoxins

 Water Quality

Characteristics

Newcombe, 2002 (WRF 446) Removal of Algal T

• xins from

Drinking Water Using ozone and GAC

Dose: Residual Curves

Ozone and Microsystin

Lab Grade water??

Ozonation of Microsystin

Newcombe, 2002 (WRF 446) Removal

• f Algal T
• xins from

Drinking Water Using ozone and GAC

Ozonation of Anatoxin-a

Newcombe, 2002 (WRF 446) Removal

• f Algal T
• xins from

Drinking Water Using ozone and GAC

Ozonation of Saxitoxins

Newcombe, 2002 (WRF 446) Removal

• f Algal T
• xins from

Drinking Water Using ozone and GAC

Structural Refresher

CEE 697z - Lecture #30

 Anatoxin-a  Saxitoxin  Microsystin  Cylindrospermopsin

Comparison in Myponga Water

Newcombe, 2002 (WRF 446) Removal

• f Algal T
• xins from

Drinking Water Using ozone and GAC

GAC removal of Saxitoxins

 Hope Valley water

GAC and more Saxitoxins

 Hope Valley Water

Newcombe, 2002 (WRF 446) Removal of Algal T

• xins from Drinking

Water Using ozone and GAC

GAC removal of Microsystins

Summary

Newcombe, 2002 (WRF 446) Removal of Algal T

• xins from Drinking

Water Using ozone and GAC

Oxidation: Summary Kinetics

Wert et al., 2014 (WRF 4406) Release of Intracellular metabolites from Cyanobacteria during O id i P

Structural Refresher

CEE 697z - Lecture #30

 Anatoxin-a  Saxitoxin  Microsystin  Cylindrospermopsin

Wert et al., 2014 (WRF 4406) Release of Intracellular metabolites from Cyanobacteria during Oxidation Processes

Wert et al., 2014 (WRF 4406) Release of Intracellular metabolites from Cyanobacteria during Oxidation Processes

Membrane removal of Cylindrospermopsin

Control of Intracellular cyanotoxins

Control of Extracellular Cyanotoxins

Cylindrospermopsin

Treatment summary

 da

From: Cyanobacteria and Cyanotoxins: Information for Drinking Water Systems , USEPA , July 2012

Managing a Cyanotoxin Event

From: Sklener, Westrick & Szlag, 2014

From: Sklenar, Westrick & Szlag, 2014

From: Sklenar, Westrick & Szlag, 2014

From: Sklenar, Westrick & Szlag, 2014

From: Sklenar, Westrick & Szlag, 2014

WTP Response to an HAB Event



Do not use pre‐chlorination for improved coagulation or reduced coagulant dosing during a cyanobacterial bloom unless comprehensive testing has identified a dose high enough to destroy released toxins. Do not apply pre‐chlorination when cyanobacteria producing MIB or geosmin are present.



Potassium permanganate dosing may be applied for the control of manganese and iron in the presence of A. circinalis and M. aeruginosa.



Practice pH control to pH > 6 if this is not part of normal operations. This will reduce the risk of cell lysis and metabolite release during treatment.



Optimize NOM removal using the criteria ΔC/C0 DOC, UV, and color ≤ 0.05 and the cell removal should be optimized as well.



While turbidity cannot be used as an indicator of the presence of cyanobacteria or cell concentration, use the decrease in settled water turbidity with coagulant dose as a surrogate for, or indicator of, cell removal if the initial turbidity is ≈10 NTU or above.



If the presence of cyanobacteria results in increased coagulant demand to achieve improved settled water turbidity the application of a particulate settling aid, or even powdered activated carbon, may lead to improvements.



Although removal of cyanobacteria through conventional coagulation can be very effective, 100% cell removal is unlikely in normal full scale operations. In the event of high cell numbers entering the plant monitor for cell carryover and accumulation in clarifiers, this can lead to serious water quality problems if not rectified.



Once captured in the sludge, cyanobacteria can remain viable and multiply over a period of at least 2‒3

• weeks. Simultaneously, within one day some cells in the sludge will lyse and release NOM and metabolites.

Newcombe, 2014 (WRF 4315, in progress) Optimizing Conventional Treatment for Removal of Cyanobacteria and T

• xins

CEE 697z - Lecture #30

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